JPH10212286A - Photoinitiator, energy ray-hardenable composition containing the same and hardened material thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new sulfonium salt having a specific structure and useful as a photoinitiator. SOLUTION: This new sulfonium salt is represented by formula I X is a group of formula II (R5 to R8 are each H, a halogen, OH, a 1-15C aliphatic, nitro, alkoxy, etc.); R1 to R4 are each the same as the R5 to R8 ; Z is an anion of the formulas MQp-m or BYa Rb [M is P, As or Sb; Q is a halogen; (p) is 4-6; (m) is 0 or 1; (a) and (b) are each 0-4 and (a)+(b) is 4; Y is a halogen or OH; R is an electron attractive group or a phenyl substituted with a halogen]; (m) is 1 or 2}. The compound of formula I is obtained by reacting a thioxanthone-based compound of formula III with a thioxanthone sulfoxide compound of formula IV under a dehydrating condition of a strong acid. An energy ray-hardenable composition including the compound of formula I and cationically polymerizable material provides a hardened material good in compatibility and preservation stability, especially excellent in hardenability, gloss, etc., even in a pigment system, and having an excellent properties.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel sulfonium salt having a specific structure, a photopolymerization initiator comprising the same,
The present invention relates to an energy ray-curable composition containing the composition, which can be cured by irradiation with energy rays, and a cured product thereof.

[0002]

2. Description of the Related Art Photopolymerizable compositions have been actively studied in the fields of printing inks, paints, coatings, liquid resist inks, etc. from the demands of energy saving, space saving, and non-polluting properties, and their practical use has been studied. . However, most of these studies were based on radical polymerization reactions of double bonds. Cationic polymerizable substances, such as epoxy resins, are excellent in physical properties, but are difficult to photopolymerize, and resin materials with double bonds introduced by acrylic modification have been mainly used. I have.

[0003]

In curing an epoxy resin by light, for example, US Pat.
No. 76 proposes a method of polymerizing an epoxy resin by using a photosensitive aromatic diazonium salt as a photopolymerization initiator, decomposing the photopolymerization initiator by light irradiation, and releasing a Lewis acid. However, aromatic diazonium salts release nitrogen gas simultaneously with Lewis acid by photolysis,
For this reason, when the thickness of the epoxy resin is 15 μm or more, the coating film foams and is not suitable for thick coating. Furthermore, a mixture of a photopolymerization initiator and an epoxy resin has a problem in storage stability, such as curing gradually progressing even when no light is present, and it is difficult to form a stable one-part composition. . In order to overcome the drawbacks of the above diazonium salt-based initiator, various studies have been made, and aromatic sulfonium salt-based or aromatic iodonium salt-based initiators and the like containing them as techniques for improving thick coating properties and storage stability Curable resin composition
No. -14278, Japanese Patent Publication No. 52-14277,
JP-A-54-53181, JP-B-59-1958.
No. 1 publication. However, compositions containing these aromatic onium salts have a disadvantage that they are poor in curability as compared with diazonium salts, and in the case of aromatic sulfonium salts, the odor of the cured product has been a problem. To overcome such drawbacks, Japanese Patent Application Laid-Open No. 56-5542
No. 0 publication proposes an aromatic sulfonium salt having a specific group. This is not sufficient, although the above disadvantages have been somewhat overcome. In addition, curing with a pigment-based initiator is insufficient, and no specific proposal has been made. As the field of use of the photopolymerization composition expands, providing a new photopolymerization initiator is an important technical problem in order to meet market requirements.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, they have found that a specific photopolymerization initiator has excellent storage stability, compatibility, and curability. The present invention was found to be excellent in curability, and found that the cured product had little odor. That is, the present invention provides (1) general formula (1)

[0005]

Embedded image

In the formula, X is a group represented by the formula (2)

[0007]

Embedded image

(Wherein, R _{5 to} R ₈ each represent a hydrogen atom, a halogen atom, a hydroxyl group, a C _{1 to} C ₁₅ aliphatic, a nitro group, an alkoxy group, a phenyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, R _{1 to} R ₄ are the groups selected from R ₅ to R ₅ in the formula (2).
The same group as R _8, Z has the formula (3)

[0009]

Embedded image _{MQ pm (OH) m (3} ) ( wherein, M is a phosphorus atom, an arsenic atom or an antimony atom, Q is a halogen atom, p is an integer of 4 to 6, m is Or an integer of 0 or 1.) or Formula (4)

[0010]

## STR00008 ## BY _a R _b (4)

Wherein B is a boron atom, and a and b are 0 to
4 is an integer, where a + b is 4 and Y
Represents a halogen atom or a hydroxyl group, and R represents a phenyl group substituted with at least one electron-withdrawing group or at least two halogen atoms. ) Represented by
n represents an integer of 1 or 2, respectively. (2) a photopolymerization initiator (B) containing a sulfonium salt as described in (1) as an active ingredient; (3) a cationically polymerizable substance (A); and a sulfonium salt as described in (1). An energy ray-curable composition comprising: (4)
The present invention relates to a cured product of the energy ray-curable composition according to the item (3).

The cationically polymerizable substance (A) used in the present invention
Examples thereof include cationic polymerizable compounds such as epoxy resin, styrene and vinyl ether, and cyclic ethers such as spiroorthoester, bicycloorthoester and spiroorthocarbonate. Examples of the epoxy resin include conventionally known aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, and epoxy monomers and episulfide monomers. Here, examples of the aromatic epoxy resin include a polyhydric phenol having at least one aromatic nucleus or a polyglycyl ether of an alkylene oxide adduct thereof, such as bisphenol A such as bisphenol A, bisphenol F, and bisphenol S. Glycidyl ethers produced by reacting a compound or an alkylene oxide (eg, ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of a bisphenol compound with epichlorohydrin;
Novolak type epoxy resins (for example, phenol / novolak type epoxy resin, cresol / novolak type epoxy resin, brominated phenol / novolak type epoxy resin, etc.), trisphenol methane triglycidyl ether and the like. Further, specific examples of the alicyclic epoxy resin include 3,4-epoxycyclohexylmethyl-
3,4-epoxycyclohexanecarboxylate, bis- (3,4-epoxycyclohexylmethyl) adipate, 2- (3,4-epoxycyclohexyl-5,5
-Spiro-3,4-epoxy) cyclohexanone-meta-dioxane, bis (2,3-epoxycyclopentyl) ether, EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd., alicyclic epoxy resin, softening point 71 ° C.) and the like. No.

Further, examples of aliphatic epoxy resins include polyglycidyl ethers of aliphatic polyhydric alcohols and alkylene oxide adducts thereof, and typical examples thereof are diglycidyl ether of 1,4-butanediol, 1,6 -Aliphatic polyhydric alcohols such as diglycidyl ether of hexanediol, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, diglycidyl ether of polyethylene glycol, diglycidyl ether of propylene glycol, ethylene glycol, propylene glycol, and glycerin; And polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide, propylene oxide) to the polymer. It is. Further, examples of the epoxide monomers include monoglycidyl ethers of aliphatic higher alcohols, phenol, cresol, butylphenol, and monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxide thereto.

Examples of the cationically polymerizable vinyl compound include triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, cyclohexane-1,4-dimethylol divinyl ether, 1,4-
Butanediol divinyl ether,

[0015]

Embedded image

And

[0017]

Embedded image

And the like. These cationically polymerizable organic materials may be used alone or as a mixture of two or more.

Examples of the sulfonium salt represented by the general formula (1) used in the present invention include: (1) a thioxanthone compound represented by the general formula (6)

[0020]

Embedded image

(Wherein, R _{1 to} R ₄ have the same meanings as R _{1 to} R ₄ in formula (1)) and a thioxanthone sulfoxide compound represented by formula (7)

[0022]

Embedded image

(Wherein, R _{5 to} R ₈ have the same meanings as R _{5 to} R ₈ in formula (2)) by utilizing a known sulfonium salt formation reaction to form a sulfonium salt. (2) Partial oxidation of general formula (6) is performed, and in this case, a thioxanthone-based compound substantially represented by general formula (6) and general formula (7) are used. The represented thioxanthone sulfoxide compound forms an equimolar amount of the mixture and decomposes a strong acid (eg, methanesulfonic acid, perfluoromethanesulfonic acid, sulfuric acid, etc.) under dehydrating conditions (eg, using phosphoric anhydride, acetic anhydride, etc.). And reacting the compound of the general formula (6) with the compound of the general formula (7) to obtain a sulfonium salt (hereinafter referred to as a second method). Can be synthesized. Industrially, the second method is preferred. The second method will be described more specifically.

Thioxanthone compounds represented by the general formula (6) (specific examples are 2,4-diethoxythioxanthone, 2,4-dipropylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone,
1-chloro-4-propoxythioxanthone, 2-hydroxy-3,4-dimethylthioxanthone, 1-methoxythioxanthone, 2-methoxythioxanthone, 3-
Methoxythioxanthone, 4-methoxythioxanthone, 1-methyl-4-hydroxythioxanthone, 1-
Methyl-4-chlorothioxanthone, 1,2-dimethyl-4-chlorothioxanthone, 1,3-dimethyl-4-
Chlorothioxanthone, 3-nitrothioxanthone, 3
-Ethoxythioxanthone, 1,3,4-trimethyl-
4-methoxycarbonyl-thioxanthone, 2-methoxycarbonyl-4-methylthioxanthone, 2-phenylthioxanthone, 1-methoxycarbonylthioxanthone, 1-ethoxycarbonyl-3-nitrothioxanthone, 1-ethoxycarbonyl-3-ethoxythioxanthone, 2- Isopropyl-4-methylthioxanthone, 2,4-dimethyl-1-chlorothioxanthone, 1
-Methyl-4-dodecylthioxanchiton, 2-octyloxy-4-methylthioxanthone, 1,4-diallyloxythioxanthone, 2-cyclohexylthioxanthone, 1,4-diacetyloxythioxanthone, 1
-Bromo-2,4-dimethylthioxanthone and the like. ) Using a known method, for example, an oxidizing agent (eg, hydrogen peroxide, potassium permanganate, peracetic acid, iodosobenzene, iodosobenzene diacetate, potassium persulfate, sodium periodate, etc.). Oxidizes to For good results, it is preferred to use about 0.2 to 0.7 moles of oxidizing agent per mole of sulfur atom in the molecule. If desired, the reaction can be promoted using a solvent. Examples of solvents that can be used include organic acids such as acetic acid, alcohols such as sulfuric acid and ethanol, and aromatic organic solvents such as benzene and monochlorobenzene. In the partial oxidation of the thioxanthone compound, satisfactory results can be obtained if the temperature is in the range of 0 to 100 ° C. The obtained thioxanthone-based compound and thioxanthone sulfoxide compound (represented by the general formula (7), and specific examples thereof include 2,4-diethoxythioxanthone-10-sulfoxide, 2,4-dipropylthioxanthone-10-sulfoxide, -Isopropylthioxanthone-10-
Sulfoxide, 2-chlorothioxanthone-10-sulfoxide, 1-chloro-4-propoxythioxanthone-10-sulfoxide, 1-methoxythioxanthone-
10-sulfoxide, 2-methoxythioxanthone-1
0-sulfoxide, 3-methoxythioxanthone-10
-Sulfoxide, 4-methoxythiosanton-10-sulfoxide, 1-methyl-4-chlorothioxanthone-
10-sulfoxide, 1,2-dimethyl-4-chlorothioxanthone-10-sulfoxide, 3-nitrothioxanthone-10-sulfoxide, 3-ethoxythioxanthone-10-sulfoxide, 1,3,4-trimethyl-4-methoxycarbonylthioxanthone -10-sulfoxide, 2-methoxycarbonyl-4-methylthioxanthone-10-sulfoxide, 2-phenylthioxanthone-10-sulfoxide, 1-methoxycarbonylthioxanthone-10-sulfoxide, 1-ethoxycarbonyl-3-nitrothioxanthone-10- Sulfoxide, 1-ethoxycarbonyl-3-ethoxythioxanthone-10-sulfoxide, 2-isopropyl-4-
Methylthioxanthone-10-sulfoxide, 2,4-
Dimethyl-1-chlorothioxanthone-10-sulfoxide, 2,4-dimethyl-1-chlorothioxanthone-
10-sulfoxide, 1-methyl-4-dodecylthioxanthone-10-sulfoxide, 2-octyloxy-
4-methylthioxanthone-10-sulfoxide, 2-
Cyclohexylthioxanthone-10-sulfoxide,
In order to carry out the reaction of the mixture of 1,4-diacetyloxythioxanthone-10-sulfoxide, 1-bromo-2,4-dimethylthioxanthone and the like, a sufficient dehydrating agent (for example, phosphoric anhydride, acetic anhydride, concentrated sulfuric acid, etc.) ) And strong acids (eg, methanesulfonic acid, perfluoromethanesulfonic acid, concentrated sulfuric acid, etc.). The temperature which can be employed for performing the partial oxidation of the thioxanthone-based compound and for performing the dehydration and the protonation is, for example, 0 ° C to 10 ° C.
0 ° C., preferably 0 ° C. to 80 ° C.

The reaction of the thioxanthone compound with the thioxanthone sulfoxide compound can be carried out within 1 to 10 hours under the above-mentioned reaction conditions, and after completion of the reaction, the obtained component is converted to the corresponding sulfonium salt. Dehydration and protonation can be performed. Thereafter, an alkali metal salt having an anion moiety of Formula (3), Formula (4) or Formula (5) (for example, NaSb ₆ ,
_{NaPF 6, NaBF 4, NaSbF 5} OH, KSbF 6, KPF 6, KAsF 6, KS
_{bF 5 OH, LiB (C 6} F 5) 4, LiB (C 6 F 5) 2 F 2, LiB (C 6 H 4 CF 3) 4,
NaB (C ₆ F ₅ ) ₄ , LiBF ₃ (C ₆ F ₅ ), LiB (C ₆ H ₃ F ₂ ) ₄ etc.) solution, or cooled according to specific conditions, said alkali metal salt The metathesis reaction can be carried out by directly pouring the reaction mixture into an aqueous solution of Next, a desired sulfonium salt can be obtained using a known recovery method (eg, filtration). If desired, it can be purified by a recrystallization method using a solvent such as alcohols.

Specific examples of the compound represented by the general formula (1) include the compounds shown in the following Table 1.

[0027]

TABLE 1 TABLE _{1 X No. R 1 ~R 4 Z} - n R 5 ~R 8 1. _{R 1 = H, R 2 =} 2- propyl ^{_{PF 6 - 1 R 5 = H}} , R 6 = 2- propyl R ₃ = 4-propyl, R ₄ = HR ₇ = 4- propyl, R ₈ = H 2. _{R 1 = H, R 2 =} 1- methoxy ^{_{SbF 6 - 1 R 5 = H}} , R 6 = 1- methoxy _{R 3, R 4 = HR 7} , R 8 = H 3. _{R 1 = H, R 2 =} 1- methyl ^{_{PF 6 - 1 R 5 = H}} , R 6 = 1- methyl R ₃ = 4-chloro, R ₄ = HR ₇ = 4- chloro, R ₈ = H 4. _{R 1 = H, R 2 =} 1- methyl ^{_{SbF 6 - 1 R 5 = H}} , R 6 = 1- methyl R ₃ = 2-methyl, R ₄ = 4-chloro R ₇ = 2-methyl, R ₈ = 4 -Chloro5. _{R 1 = H, R 2 =} 1- methoxycarbonyl ^{_{SbF 6 - 1 R 5 = H}} , R 6 = 1- Metokishikaru alkenyl R _3, R ₄ = H Boniru _{R 7, R 8 = H 6} . _{R 1 = H, R 2 =} 1- ethoxycarbonyl ^{_{PF 6 - 1 R 5 = H}} , R 6 = 1- Etokishikaru alkenyl R ₃ = _3, = _ethoxy, R ₄ = H Boniru R ₇ = 3- ethoxy, R ₈ = H7. _{R 1 = H, R 2 =} 1- methyl _{B (C 6 F 5) 4} - 1 R 5 = H, R 6 = 1- methyl R ₃ = 4-Dodejiru, R ₄ = HR ₇ = 4- dodecyl, R ₈ = H

The curable composition of the present invention is used in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the cationically polymerizable substance (A).
Is prepared by mixing the sulfonium salt (B) shown as an essential component, but the appropriate ratio is determined by the type of cationic polymerizable substance or energy ray, the amount of irradiation, the desired curing time,
It is appropriately determined by considering various factors such as temperature, humidity, and coating film thickness. To facilitate dissolution of the sulfonium salt in the cationically polymerizable substance, the sulfonium salt can be used by dissolving it in a solvent (eg, propylene carbonate, carbitol, carbitol acetate, butyrolactone) in advance. The curable composition of the present invention can be prepared by a method such as mixing, dissolving or kneading the cationically polymerizable substance and the sulfonium salt at the above composition ratio.

The curable composition of the present invention can be cured to a touch-to-touch state or a solvent-insoluble state after 0.1 seconds to several minutes by irradiating energy rays such as ultraviolet rays. Any suitable energy ray may be used as long as it has an energy that induces the decomposition of the sulfonium salt. Preferably, the energy ray is from 2000 Å to 70000 Å obtained from a high-low pressure mercury lamp, a xenon lamp, a germicidal lamp, a laser beam or the like. High energy rays such as electromagnetic wave energy having a wavelength, electron beam, X-ray, and radiation are used. Exposure to an energy ray depends on the intensity of the energy ray, but usually about 0.1 to 10 seconds is sufficient. However, it is preferred to spend more time on relatively thick painted objects. From 0.1 seconds to several minutes after the irradiation with the energy beam, most compositions are dried by touch by cationic polymerization, but it is sometimes preferable to use heating in combination to promote the cationic polymerization reaction.
The composition of the present invention further includes a solvent for dilution, a non-reactive resin for modification, and a (meth) acrylate compound (for example, a bisphenol A type epoxy resin) as long as the cationic polymerization is not impaired. And oligomers such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyester poly (meth) acrylate, which are reaction products of epoxy resin such as novolak type epoxy resin and (meth) acrylic acid, and 2-hydroxyethyl (meth) Acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate,
And a monomer such as trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate. When a (meth) acrylate compound is used, a photoradical polymerization initiator (for example, 1-hydroxycyclohexylphenyl ketone, acetophenone dimethyl ketal, benzoylmethyl ether, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc.) It is preferred to use Further, for example, an organic carboxylic acid or an acid anhydride may be used for the purpose of improving electric characteristics, or a polyol or other flexible prepolymer may be mixed for the purpose of imparting rubber elasticity.

The composition of the present invention may contain an inert pigment (for example, carbon black, graphite, molybdenum,
Inorganic pigments such as bengara, rutile type titanium dioxide coated with titanium dioxide or aluminum oxide, and organic pigments such as cyanine green, cyanine blue, Hansa yellow, benzidine yellow, brilliant carmine 6B, leg red C, permanent red F5R, and the like. Can be. ), Dyes, fillers, antistatic agents, flame retardants, antifoaming agents, flow regulators, sensitizers, accelerators, light stabilizers and the like. The energy ray-curable composition of the present invention can be added to metal, wood, rubber, plastic, glass, ceramic products and the like. Further, specific applications of the energy ray-curable composition of the present invention include paints, coatings, inks, resists, liquid resists, adhesives, molding materials, casting materials, putties, glass fiber impregnating agents, fillers, and the like. Is mentioned.

[0031]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Parts in Examples are parts by weight.

(Synthesis Example of Sulfonium Salt Represented by Formula (1)) Example 1 A mixture comprising 25.4 parts of 2-isopropylthioxanthone, 300 parts of acetic anhydride, and 1 part of sodium tungstate hydrate was mixed with 50 to 70 parts. At 1 ° C., 11.5 parts of 35% hydrogen peroxide were added dropwise and allowed to react for another 2 hours.
Then, the mixture was reacted at 80 ° C. for about 8 hours, and then 217.5 parts of a 6% aqueous NaSbF ₆ solution was added to the reaction mixture, and the precipitated yellow solid was filtered, washed sufficiently with water, and then washed. Recrystallization from methanol, melting point 75-85 ° C
A pale yellow solid was obtained. The yield of the recrystallized product was 30 parts, and the elemental analysis value was as follows, and it was confirmed that the product had the structural formula represented by the following formula. Element Actual measured value (% by weight) Calculated value (% by weight) Carbon 51.64 51.70 Hydrogen 3.70 3.66 Sulfur 8.66 8.62 Antimony 16.31 16.38 Fluorine 15.28 15.33

[0033]

Embedded image

Example 2 29 parts of 2-chlorothioxanthone, 300 parts of acetic anhydride,
To a mixture consisting of 1 part of sodium tungstate dihydrate and 400 parts of methanesulfonic acid, 11.5 parts of 35% hydrogen peroxide was added dropwise at 50 to 70 ° C., and the mixture was further reacted for 2 hours, and then reacted at 80 ° C. for 8 hours. Then, 141.4 parts of a 6% aqueous NaPF ₆ solution was added to the reaction mixture, and the precipitated yellow solid was filtered, sufficiently washed with water, and then recrystallized from methanol to give a pale yellow solid having a melting point of 140 to 155 ° C. A solid was obtained. The yield of the product obtained by recrystallization from methanol was 31 parts, and the elemental analysis values were as follows. Element Actual measured value (% by weight) Calculated value (% by weight) Carbon 53.05 53.12 Hydrogen 3.71 3.76 Sulfur 8.83 8.86 Phosphorus 4.29 4.28 Fluorine 15.75 15.75 Chlorine 9 .74 9.80 This product was a sulfonium salt represented by the following structural formula. Structural formula

[0035]

Embedded image

Examples 3 and 4, Comparative Example 1 Each component was blended according to the blending composition (the numerical values are parts by weight) shown in Table 2 and kneaded with a three-roll mill to obtain an energy ray-curable composition. Place this on an aluminum plate
200 mJ from a distance of 8 cm with a metal halide lamp (80 w / cm ² ).
/ Cm ² and cured. Curability of the obtained cured film,
The cured coatings were tested for gloss. Table 3 shows the results.
Shown in

Curability: The cured coating was left for 24 hours, rubbed 50 times with absorbent cotton impregnated with methyl ethyl ketone, and the appearance of the coating was observed. ○ ・ ・ ・ ・ No abnormality in the coating film. Δ: The gloss of the coating film is slightly reduced. X: The coating film was dissolved.

Mitsuzawa: The surface of the cured coating film was visually judged.・ ・ ・: Good gloss. Δ: There is slight cloudiness. X: No gloss at all.

[0039]

Table 2 Example Comparative Example 3 4 1 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 85 69 85 Bisphenol A diglycidyl ether 20 Sulfonium salt obtained in Example 1 3 Example 2 3 UVI-6990 * 16 Others Titanium dioxide (rutile type) 98 98 98 Polyester resin * 2 10 6 10 Surfactant (L-7604) * 3 0.4 0.4 0.4 Curability ○ ○ × Hikarizawa ○ ○ ×

Note) * 1 UVI-6990:
Photo-cationic polymerization initiator manufactured by Union Carbide Co., Ltd.
Propylene carbonate 50% diluted product. Structural formula

[0041]

Embedded image

And

[0043]

Embedded image

* 2 Polyester resin: "Vylon 220" manufactured by Toyobo Co., Ltd., molecular weight: 2,000 to 3,000. * 3 L-7604: manufactured by Nippon Unicar, Ltd., a surfactant.

As is clear from the results in Table 3, the energy ray-curable composition of the present invention has excellent curability, and the cured product obtained therefrom has excellent gloss and the like.

[0046]

The energy ray-curable composition containing the photopolymerization initiator of the present invention has good compatibility and storage stability.
Particularly in the case of pigments, the curability and gloss are excellent, and a cured product having excellent physical properties is provided.

Claims (4)

[Claims] 1. A compound of the general formula (1) In the formula, X represents a group represented by the formula (2): (Wherein, R _{5 to} R ₈ each represent a hydrogen atom, a halogen atom, a hydroxyl group, a C _{1 to} C ₁₅ aliphatic group, a nitro group, an alkoxy group, a phenyl group, an alkoxycarbonyl group, or an alkylcarbonyloxy group. R _{1 to} R ₄ are the same groups as R _{5 to} R ₈ in the formula (2), and Z is a group represented by the formula (3): MQ _pm (OH) m ( 3) (where M is a phosphorus atom, an arsenic atom or an antimony atom, Q is a halogen atom, p is an integer of 4 to 6, and m is an integer of 0 or 1) or a formula (4) ## STR4 ## bY _a R _b (4) (wherein, B is a boron atom, a and b are integers ranging from 0 to 4, where a + b is 4, Y is a halogen atom or R is substituted with at least one electron withdrawing group or at least two halogen atoms. The anion represented by.) Which represents a phenyl group and n represents an integer of 1 or 2, respectively. A sulfonium salt represented by｝. 2. A photopolymerization initiator (B) comprising the sulfonium salt according to claim 1 as an active ingredient. 3. An energy ray-curable composition comprising a cationically polymerizable substance (A) and the sulfonium salt according to claim 1. 4. A cured product of the energy ray-curable composition according to claim 3.